African American Race is an Independent Risk Factor in Survival from Initially Diagnosed Localized Breast Cancer

Temporal Association Rule Mining: Race-Based Patterns of Treatment-Adverse Events in Breast Cancer Patients Using SEER-Medicare Dataset

PURPOSE

Disparities in the screening, treatment, and survival of African American (AA) patients with breast cancer extend to adverse events experienced with systemic therapy. However, data are limited and difficult to obtain. We addressed this challenge by applying temporal association rule (TAR) mining using the SEER-Medicare dataset for differences in the association of specific adverse events (AEs) and treatments (TRs) for breast cancer between AA and White women. We considered two categories of cancer care providers and settings: practitioners providing care in the outpatient units of hospitals and institutions and private practitioners providing care in their offices.

PATIENTS AN METHODS

We considered women enrolled in the Medicare fee-for-service option at age 65 who qualified by age and not disability, who were diagnosed with breast cancer with attributed patient factors of age and race, marital status, comorbidities, prior malignancies, prior therapy, disease factors of stage, grade, and ER/PR and Her2 status and laterality. We included 141 HCPCS drug J codes for chemotherapy, biotherapy, and hormone therapy drugs, which we consolidated into 46 mechanistic categories and generated AE data. We consolidated AEs from ICD9 codes into 18 categories associated with breast cancer therapy. We applied TAR mining to determine associations between the 46 TR and 18 AE categories in the context of the patient categories outlined. We applied the spark.mllib implementation of the FPGrowth algorithm, a parallel version called PFP. We considered differences of at least one unit of lift as significant between groups. The model's results demonstrated a high overlap between the model's identified TR-AEs associated set and the actual set.

RESULTS

Our results demonstrate that specific TR/AE associations are highly dependent on race, stage, and venue of care administration.

CONCLUSIONS

Our data demonstrate the usefulness of this approach in identifying differences in the associations between TRs and AEs in different populations and serve as a reference for predicting the likelihood of AEs in different patient populations treated for breast cancer. Our novel approach using unsupervised learning enables the discovery of association rules while paying special attention to temporal information, resulting in greater predictive and descriptive power as a patient's health and life status change over time.

Racial Disparities in Breast Cancer Treatments and Adverse Events in the SEER-Medicare Data

Despite lower incidence rates, African American (AA) patients have shorter survival from breast cancer (BC) than white (W) patients. Multiple factors contribute to decreased survival, including screening disparities, later presentation, and access to care. Disparities in adverse events (AEs) may contribute to delayed or incomplete treatment, earlier recurrence, and shortened survival. Here, we analyzed the SEER-Medicare dataset, which captures claims from a variety of venues, in order to determine whether the cancer care venues affect treatment and associated adverse events. We investigated a study population whose claims are included in the Outpatient files, consisting of hospital and healthcare facility venues, and a study population from the National Claims History (NCH) files, consisting of claims from physicians, office practices, and other non-institutional providers. We demonstrated statistically and substantively significant venue-specific differences in treatment rates, drugs administered, and AEs from treatments between AA and W patients. We showed that AA patients in the NCH dataset received lower rates of treatment, but patients in the Outpatient dataset received higher rates of treatment than W patients. The rates of recorded AEs per treatment were higher in the NCH setting than in the Outpatient setting in all patients. AEs were consistently higher in AA patients than in W patients. AA patients had higher comorbidity indices and were younger than W patients, but these variables did not appear to play roles in the AE differences. The frequency of specific anticancer drugs administered in cancer- and venue-specific circumstances and their associated AEs varied between AA and W patients. The higher AE rates were due to slightly higher frequencies in the administration of drugs with higher associated AE rates in AA patients than in W patients. Our investigations demonstrate significant differences in treatment rates and associated AEs between AA and W patients with BC, depending on the venues of care, likely contributing to differences in outcomes.

Awakening of Dormant Breast Cancer Cells in the Bone Marrow

Up to 40% of patients with breast cancer (BC) have metastatic cells in the bone marrow (BM) at the initial diagnosis of localized disease. Despite definitive systemic adjuvant therapy, these cells survive in the BM microenvironment, enter a dormant state and recur stochastically for more than 20 years. Once they begin to proliferate, recurrent macrometastases are not curable, and patients generally succumb to their disease. Many potential mechanisms for initiating recurrence have been proposed, but no definitive predictive data have been generated. This manuscript reviews the proposed mechanisms that maintain BC cell dormancy in the BM microenvironment and discusses the data supporting specific mechanisms for recurrence. It addresses the well-described mechanisms of secretory senescence, inflammation, aging, adipogenic BM conversion, autophagy, systemic effects of trauma and surgery, sympathetic signaling, transient angiogenic bursts, hypercoagulable states, osteoclast activation, and epigenetic modifications of dormant cells. This review addresses proposed approaches for either eliminating micrometastases or maintaining a dormant state.

Fibroblasts as Turned Agents in Cancer Progression

Differentiated epithelial cells reside in the homeostatic microenvironment of the native organ stroma. The stroma supports their normal function, their G0 differentiated state, and their expansion/contraction through the various stages of the life cycle and physiologic functions of the host. When malignant transformation begins, the microenvironment tries to suppress and eliminate the transformed cells, while cancer cells, in turn, try to resist these suppressive efforts. The tumor microenvironment encompasses a large variety of cell types recruited by the tumor to perform different functions, among which fibroblasts are the most abundant. The dynamics of the mutual relationship change as the sides undertake an epic battle for control of the other. In the process, the cancer “wounds” the microenvironment through a variety of mechanisms and attracts distant mesenchymal stem cells to change their function from one attempting to suppress the cancer, to one that supports its growth, survival, and metastasis. Analogous reciprocal interactions occur as well between disseminated cancer cells and the metastatic microenvironment, where the microenvironment attempts to eliminate cancer cells or suppress their proliferation. However, the altered microenvironmental cells acquire novel characteristics that support malignant progression. Investigations have attempted to use these traits as targets of novel therapeutic approaches.

Dermatologic toxicities of chemotherapy: an educational intervention for skin of color women with breast cancer

Minority patients are more likely to require dose adjustments for chemotherapy, with cultural barriers and access to medical care cited as contributory factors.

Objective

We sought to pilot an educational intervention, in the form of a pamphlet, to evaluate the effectiveness of this tool in teaching skin of color (SoC) patients about potential dermatologic toxicities of chemotherapy that are relevant to their skin type.

Methods

At a chemotherapy infusion center, SoC patients (n = 26) who were receiving chemotherapy for breast cancer voluntarily consented to read an educational pamphlet and complete a series of survey questions before and after this educational intervention.

Results

Most participants identified as female (96%), African American/Black (81%), and non-Hispanic (85%); all respondents had obtained at least a high school degree. Survey responses revealed a significant increase in knowledge about the potential dermatologic effects of cancer treatment after this intervention. Notably, 100% of participants either agreed or strongly agreed that they would like to see other doctors use this educational tool as a form of patient education, that they would recommend this pamphlet to other patients who are starting cancer treatment, and that the pamphlet was easy to understand.

Limitations

Limitations of this study include small sample size and single-institution recruitment, which may limit generalizability. Furthermore, this study only included patients who are proficient in English.

Conclusion

This study pilots an effective educational tool that addresses dermatologic toxicities of chemotherapy that are relevant to SoC patients. Further multi-institutional studies with larger sample sizes and translation to other languages can overcome the limitations of this pilot study.

Women's health and night shift work: Potential targets for future strategies in breast cancer (Review)

Breast cancer is the leading cause of cancer-associated amongst women worldwide. Several studies have shown that individual, environmental and occupational factors can serve an important role in the onset of breast cancer; although the majority of studies have demonstrated this association, and several studies have investigated the biological pathways, it is impossible to describe with certainty the causal relationship that involve circadian rhythm disruption and melatonin dysregulation with the oncogenic processes. Over the years, due to the introduction of more effective screening tools, an increase in the incidence of breast cancer as well as a decrease in the age at diagnosis has been witnessed. Subsequently, an increasing number of individuals have obtained care at a younger age, which has meant that after surgery and chemotherapy, these workers have had to return to work. In light of these paradigmatic changes, the aim of the present review was to identify potential targets for future organisational strategies that should be adopted in the workplace by occupational physicians, both for prevention and for the return-to-work process of working women who have suffered from breast cancer.

Differences in Breast Cancer Presentation at Time of Diagnosis for Black and White Women in High Resource Settings

This paper provides a narrative review of the existing literature on differences in demographic and biological features of breast cancer at time of diagnosis between Black and White women in Canada, the United Kingdom and the United States. Electronic database searches for published peer-reviewed articles on this topic were conducted, and 78 articles were included in the final narrative review. Differences between Black and White women were compared for eight categories including age, tumour stage, size, grade, lymph node involvement, and hormone status. Black women were significantly more likely to present with less favourable tumour features at the time of diagnosis than White women. Significant differences were reported in age at diagnosis, tumour stage, size, grade and hormone status, particularly triple negative breast cancer. Limitations on the generalizability of the review findings are discussed, as well as the implications of these findings on future research, especially within the Canadian context.

Greater Survival Improvement in African American vs. Caucasian Women with Hormone Negative Breast Cancer

Background: African American women have not benefited equally from recently improved breast cancer survival. We investigated if this was true for all subsets.

Methods: We identified 395,170 patients with breast adenocarcinoma from the SEER database from 1990 to 2011 with designated race, age, stage, grade, ER and PR status, marital status and laterality, as control. We grouped patients into two time periods, 1990-2000 and 2001-2011, three age categories, under 40, 40-69 and ≥ 70 years and two stage categories, I-III and IV. We used the Kaplan-Meier and logrank tests to compare survival curves. We stratified data by patient- and tumor-associated variables to determine co-variation among confounding factors using the Pearson Chi-square test and Cox proportional hazards regression to determine hazard ratios (HR) to compare survival.

Results: Stage I-III patients of both races ≥ 70 years old, African American widowed patients and Caucasians with ER- and PR- tumors had worse improvements in survival in 2001-2011 than younger, married or hormone receptor positive patients, respectively. In contrast, African Americans with ER- (Cox HR 0.70 [95% CI 0.65-0.76]) and PR- (Cox HR 0.67 [95% CI 0.62-0.72]) had greater improvement in survival in 2001-2011 than Caucasians with ER- (Cox HR 0.81 [95% CI 0.78-0.84]) and PR- disease (Cox HR 0.75 [95% CI 0.73-0.78]). This was not associated with changes in distribution of tumor or patient attributes.

Conclusions: African American women with stage I-III ER- and PR- breast cancer had greater improvement in survival than Caucasians in 2001-2011. This is the first report of an improvement in racial disparities in survival from breast cancer in a subset of patients.

Temporally dependent accelerated failure time model for capturing the impact of events that alter survival in disease mapping

The introduction of spatial and temporal frailty parameters in survival models furnishes a way to represent unmeasured confounding in the outcome of interest. Using a Bayesian accelerated failure time model, we are able to flexibly explore a wide range of spatial and temporal options for structuring frailties as well as examine the benefits of using these different structures in certain settings. A setting of particular interest for this work involved using temporal frailties to capture the impact of events of interest on breast cancer survival. Our results suggest that it is important to include these temporal frailties when there is a true temporal structure to the outcome and including them when a true temporal structure is absent does not sacrifice model fit. Additionally, the frailties are able to correctly recover the truth imposed on simulated data without affecting the fixed effect estimates. In the case study involving Louisiana breast cancer-specific mortality, the temporal frailty played an important role in representing the unmeasured confounding related to improvements in knowledge, education, and disease screenings as well as the impacts of Hurricane Katrina and the passing of the Affordable Care Act. In conclusion, the incorporation of temporal, in addition to spatial, frailties in survival analysis can lead to better fitting models and improved inference by representing both spatially and temporally varying unmeasured risk factors and confounding that could impact survival. Specifically, we successfully estimated changes in survival around the time of events of interest.

A data-driven approach for estimating the change-points and impact of major events on disease risk

Considering the impact of events on disease risk is important. Here, a Bayesian spatio-temporal accelerated failure time model furnished an ideal situation for modeling events that could impact survival experience via spatial and temporal frailty estimates. Through a hierarchical structure, this model allowed the data to detect the change-point(s) in addition to generating the event-related estimates. Both a real data case study and a simulation study were employed for testing these methods. The results suggested that meaningful and accurate change-points could be detected. Further, accurate event-related estimates for individuals in relation to those change-points could be obtained. By allowing the data to drive the change-point choices, the models were better fitting and the inference was more accurate.

Reawakening of dormant estrogen-dependent human breast cancer cells by bone marrow stroma secretory senescence

Background

Dormant estrogen receptor positive (ER+) breast cancer micrometastases in the bone marrow survive adjuvant chemotherapy and recur stochastically for more than 20 years. We hypothesized that inflammatory cytokines produced by stromal injury can re-awaken dormant breast cancer cells.

Methods

We used an established in vitro dormancy model of Michigan Cancer Foundation-7 (MCF-7) breast cancer cells incubated at clonogenic density on fibronectin-coated plates to determine the effects of inflammatory cytokines on reactivation of dormant ER+ breast cancer cells. We measured induction of a mesenchymal phenotype, motility and the capacity to re-enter dormancy. We induced secretory senescence in murine stromal monolayers by oxidation, hypoxia and estrogen deprivation with hydrogen peroxide (H₂O₂), carbonyl-cyanide m-chlorophenylhydrazzone (CCCP) and Fulvestrant (ICI 182780), respectively, and determined the effects on growth of co-cultivated breast cancer cells.

Results

Exogenous recombinant human (rh) interleukin (IL)-6, IL-8 or transforming growth factor β1 (TGFβ1) induced regrowth of dormant MCF-7 cells on fibronectin-coated plates. Dormant cells had decreased expression of E-cadherin and estrogen receptor α (ERα) and increased expression of N-cadherin and SNAI2 (SLUG). Cytokine or TGFβ1 treatment of dormant clones induced formation of growing clones, a mesenchymal appearance, increased motility and an impaired capacity to re-enter dormancy. Stromal injury induced secretion of IL-6, IL-8, upregulated tumor necrosis factor alpha (TNFα), activated TGFβ and stimulated the growth of co-cultivated MCF-7 cells. MCF-7 cells induced secretion of IL-6 and IL-8 by stroma in co-culture.

Conclusions

Dormant ER+ breast cancer cells have activated epithelial mesenchymal transition (EMT) gene expression programs and downregulated ERα but maintain a dormant epithelial phenotype. Stromal inflammation reactivates these cells, induces growth and a mesenchymal phenotype. Reactivated, growing cells have an impaired ability to re-enter dormancy. In turn, breast cancer cells co-cultured with stroma induce secretion of IL-6 and IL-8 by the stroma, creating a positive feedback loop.

The influence of marital status and race/ethnicity on risk of mortality for triple negative breast cancer

Purpose

To assess the effect of marital status and the role of race/ethnicity on breast cancer specific mortality in women with triple negative breast cancer (TNBC).

Methods

The study utilized the California Cancer Registry to identify 22,812 cases of first primary female TNBC. Unadjusted Kaplan-Meier breast cancer specific survival was computed. Cox Proportional Hazards modeling was used to compute the adjusted risk of breast cancer specific mortality for women who were single, separated, divorced, and widowed when compared with women who were married. Models were adjusted for age, stage, tumor grade, SES, and treatment with surgery, chemotherapy, hormone therapy, and radiation therapy. Hazard ratios (HR) and 95% confidence intervals (CI) were reported.

Results

Separated (HR: 1.45; 95% CI: 1.14–2.01) and widowed (HR: 1.39; 95%CI: 1.23–1.57) white women had a higher risk of mortality than white married women whereas single and divorced white women had the same risk of mortality. For Asian/Pacific Islanders (API), only single (HR: 1.55; 95% CI: 1.17–2.06) and divorced (HR:1.81; 95% CI:1.26–2.60) women had a higher risk of mortality than married women. Marital status had no influence on risk of mortality for either black or Hispanic women.

Conclusions

The risk of mortality associated with marital status is dependent on race/ethnicity. Only white and API women with TNBC have a marital advantage.

Normal Axillary Lymph Node Variability Between White and Black Women on Breast MRI

RATIONALE AND OBJECTIVES

This study aimed to determine if there were differences in the imaging features of normal lymph nodes between white and black women using magnetic resonance imaging.

MATERIALS AND METHODS

Following institutional review board approval, we identified white and black women who underwent breast magnetic resonance imaging from November 1, 2008 to December 31, 2013 at our institution. To identify normal lymph nodes for measurement, patients with any benign or malignant causes for lymph node enlargement and patients with any subsequent breast cancer in the following 2 years were excluded. Black and white women were age matched at a 1:2 ratio. The largest lymph node in each axilla was measured for the long-axis length and maximal cortical thickness. Comparisons were made between white and black women using a conditional logistic regression to control for matching.

RESULTS

There were 55 black women and 110 white women for analysis. The mean lymph node long-axis length was 14.7 ± 5.3 mm for black women and 14.4 ± 6.4 mm for white women (P = .678). The mean maximum cortical thickness was 3.3 ± 1.6 mm for black women and 2.6 ± 1.4 mm for Caucasian women (P < .001). A significantly higher percentage of black than white women had cortical thicknesses greater than threshold values of 3, 4, 5, 6, and 7 mm (P < .01 for all).

CONCLUSIONS

The normal lymph node cortical thickness in black women is significantly greater than in white women, which should be considered when deciding to recommend a lymph node biopsy.

Assessment of spatial variation in breast cancer-specific mortality using Louisiana SEER data

BACKGROUND

Previous studies suggest spatial differences in mortality for many types of cancer, including breast cancer. Identifying explanations for these spatial differences results in a better understanding of what leads to longer survival time.

METHODS

We used a Bayesian accelerated failure time model with spatial frailty terms to investigate potential spatial differences in breast cancer mortality following breast cancer diagnosis using 2000-2013 Louisiana SEER data.

RESULTS

There are meaningful spatial differences in breast cancer mortality across the parishes of Louisiana, even after adjusting for known demographic and clinical risk factors. For example, the average survival time of a woman diagnosed in Orleans parish was 1.51 times longer than that of a woman diagnosed in Terrebonne parish. Additionally, there is evidence to suggest shorter survival times in lower income parishes along the Red and Mississippi Rivers, as well as parishes with lower socioeconomic status, less access to care and fresh food, worse quality of care, and more workers in certain industries.

CONCLUSION

The addition of spatial frailties to account for an individual's geographic location is useful when analyzing breast cancer mortality data. Our findings suggest that survival following breast cancer diagnosis could potentially be improved if socioeconomic status differences were addressed, healthcare improved in quality and became more accessible, and certain industrial situations were improved for individuals diagnosed in parishes identified as having shorter average survival times.